Success!!! (Almost) Well we have tested the two compressors - charged with refrigerant and ran the chiller. Upon installation we fried one of the TXV valves so it wasn't regulating the pressure right had 0deg on the plate exchanger and high head pressure on the compressor...New TXV is on order... But - the other side ran well and we chilled the 30gal from about 80deg to 45 deg and it cycles both stages as intended and maintains the temp... ahhhh.. Relief as all my wiring and transformer, relays, plumbing etc worked.... Now it's on to the interior air/water handlers finally...

Congratulations on commissioning the chiller system! I'm not sure I understand the efficiency of it, but it sure sounds like its inspired by the HVAC systems in Vegas. I drove through there once a few years ago with my kids, and being who I am, was always trying to glimpse the massive chiller systems hidden in plain sight.

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Originally Posted by Offgr1d

Success!!! (Almost) Well we have tested the two compressors - charged with refrigerant and ran the chiller. Upon installation we fried one of the TXV valves so it wasn't regulating the pressure right had 0deg on the plate exchanger and high head pressure on the compressor...New TXV is on order... But - the other side ran well and we chilled the 30gal from about 80deg to 45 deg and it cycles both stages as intended and maintains the temp... ahhhh.. Relief as all my wiring and transformer, relays, plumbing etc worked.... Now it's on to the interior air/water handlers finally...

Success!!! (Almost) Well we have tested the two compressors - charged with refrigerant and ran the chiller. Upon installation we fried one of the TXV valves so it wasn't regulating the pressure right had 0deg on the plate exchanger and high head pressure on the compressor...New TXV is on order... But - the other side ran well and we chilled the 30gal from about 80deg to 45 deg and it cycles both stages as intended and maintains the temp... ahhhh.. Relief as all my wiring and transformer, relays, plumbing etc worked.... Now it's on to the interior air/water handlers finally...

this just plain rocks!!! I totally dig advanced HVAC systems, and chillers too... are you cooling the outer coils with a glycol loop or are your condensers strictly air-cooled?

you mentioned frying an XV, are you running inverter compressors with EEV's?

Keep up the good work!! this is my type of HVAC! similar to what im running at home..
-Christopher

The TXV was damaged upon install with getting brazing too hot is all... A simple mistake because we had a fussy connection and did it multiple times.. I'm not running any glycol yet - don't think I'll need to in my desert climate. The chiller condensers are ran to the original but modified rooftop air cooled coils. 5 fans cool the two coils..

The TXV was damaged upon install with getting brazing too hot is all... A simple mistake because we had a fussy connection and did it multiple times.. I'm not running any glycol yet - don't think I'll need to in my desert climate. The chiller condensers are ran to the original but modified rooftop air cooled coils. 5 fans cool the two coils..

Where is your field rep. Start up report? They didn't catch that?
Sorry it was just fine when the TECH. Was here? now the part is on order and will be 5-days before I can give you A/C? Maitenance said the glycol was low? Did you check that? Did maitenance actually look at the trouble codes? Or just say something because they don't know?
I used to do commercial install of 3-600 ton chillers and to many don't realize how many times a manufacturer screws up.

The TXV was damaged upon install with getting brazing too hot is all... A simple mistake because we had a fussy connection and did it multiple times.. I'm not running any glycol yet - don't think I'll need to in my desert climate. The chiller condensers are ran to the original but modified rooftop air cooled coils. 5 fans cool the two coils..

something ive used as an alternative to brazing is staybrite 8, I got criticized for using it 7 years ago when I needed to replace a cracked section of pipe and a reversing valve in one of my heatpumps.. (the old-timers said braze or die)..

but it works at much lower temperatures than brazing.. and theoretically you never have to heat the pipe enough to reach oxidation levels so a nitrogen purge isnt necessary.. (though I still ran one just because I have the taks and gear to do it)..

I havent had one joint out of the 10 or so that I have fail in 7 years. and a couple of them are right at the compressor so they take lots of temperature fluctuations and vibration...

I started out using it exclusively for reversing valves or EEV's.. but now I use it on everything.. even copper water pipes...

one thing that definitely does NOT WORK is HVAC super pro... (a glue that supposedly was good for joining HVAC pipes...).. I got notofied by my computer about a month later that the refrigerant in 'unit 2' was low.. I knew the first place to go with my leak detector solution!!..

Where is your field rep. Start up report? They didn't catch that?
Sorry it was just fine when the TECH. Was here? now the part is on order and will be 5-days before I can give you A/C? Maitenance said the glycol was low? Did you check that? Did maitenance actually look at the trouble codes? Or just say something because they don't know?
I used to do commercial install of 3-600 ton chillers and to many don't realize how many times a manufacturer screws up.

sounds like he just got the TxV too hot because of likely impurities in the pipe.. have had that issue before where the pipe was never quite clean enough so became a B**** to get the brazing rod to flow...

if its electronic it usually melts the stepper motor innards.. if its mechanical it usually messes up the needle valve or ruptures the "charged" portion of the valve...

Never heard of that? I know they are trying to sell something that I tried one time and then covered with 15% and didn't like call the silver ring which you shove in the fitting just ahead of the pipe and heat up the joint?
I want to see the braze/weld?
If vibration is such an issue in the piping/compressor? Why is there not a flex connector that can handle the job? Is this the suppliers money maker?

Never heard of that? I know they are trying to sell something that I tried one time and then covered with 15% and didn't like call the silver ring which you shove in the fitting just ahead of the pipe and heat up the joint?
I want to see the braze/weld?
If vibration is such an issue in the piping/compressor? Why is there not a flex connector that can handle the job? Is this the suppliers money maker?

on big systems there are "flex joints".. I used to replace more "vibration eliminators" on my copeland semi hermetics than I ever did on units that didnt have them..

but the customers like them because for rooftop units it kept the vibrations down in the building..

mosttime vibration becomes an issue on smaller systems as the copper walls of the tubing are thinner than on the larger size pipes.. so the likliehood of a hairline crack all the way through a pipe is higher than on large systems...

typically if im piping in a small compressor myself I leave a couple loops in a loose "coil" type pattern on the discharge and make sure I have nice wide turns on my suction line so the pipe has some room to flex each part of its length in smaller amounts.. lessening the chance of a crack...

my 3 home units are heat / cool so they run all year and I havent lost a joint in 7 years since I re-piped and re-did everything at the major zone-control install...

Yeah, I have the staybright 8 solder. I use it on the copper water stuff I do with torch. Great stuff. It's completely capable of holding high pressure joints. I've seen the same mixed reviews of it against standard brazing. Brazing is extremely hot, and my HVAC helper friend and made the error of not protecting that TXV enough with cold cloth, gel, and like mentioned a not clean enough joint. Live and learn!! Argh...
I'm waiting on the new part so next weekend we should put it in as well as a sightglass to help up diagnose our proper (happy) charge amount.. It's such a unique system it will take us a bit to iron out the kinks and get it to max efficiency.

I have a plan for my first exchanger inside and will start that project tomorrow - as I already can run 45deg water... New continuous pressure diaphragm pump comes in soon for the secondary water loop for the air handlers... So excited!!! It's starting to get warm in Vegas - hopefully I finish a handler or two before it's blazing!!